[U-Boot-Users] U-Boot wrong cpu frequency calculation when setting PLPRCR directly

Markus Klotzbücher mk at denx.de
Sat Jan 20 18:03:44 CET 2007

Dear Antonio,

Antonio Di Bacco <dibacco at libero.it> writes:

> I setup the cpu frequency of a Freescale MPC880 directly providing a value
> for the PLPRCR register. When the u-boot (1.2.0 and previous) starts, in
> file speed.c it makes a calculation to display the CPU frequency based on
> fields in PLPRCR. Working with integers it makes an approximation that
> leads to a wrong cpu frequency in my case 130 Mhz instead of 132 Mhz). As a
> consequence my clock was wrong gaining 20 minutes per day. It is easy to
> patch the problem. If someone is interested I'll give him the patch.

Please post the patch so at least it can be found in the archives later.


Markus Klotzbuecher

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